Organic waste processing method and device therefor

ABSTRACT

An organic waste processing method and device makes a mass disposal and 24 hours continuous processing possible, and can largely cut down facility and processing costs. It uses a number of roughly cut-end inverted cone shaped processing tanks  3, 3 A,  3 B, and  3 C aligned serially, a motor  17  installed on the bottom of each processing tank, a rotating shaft  19  that rotates by motor  17  drive set up passing through the top and bottom parts inside each processing tank, and stirring blades  21 , attached on rotating shaft  19 , that mix aerobic microorganism  1  and organic waste  2  to put in more than capacity amount of organic waste  2  into the upstream processing tank  3 , have a part of organic waste  2  transport from outlet  14  at upper peripheral wall of processing tank  3  to inlet  9  at the top of processing tank  3 A placed adjacently and downstream, by centrifugal force of stirring blades  21 . By repeating this process according to the number of processing tanks, a large amount of organic waste  2  is continuously aerobic fermented and turned into compost.

This U.S. patent application claims the priority of PCT InternationalApplication No. PCT/JP01/01047, filed on Feb. 14, 2001, based on thepriority of Japanese Patent Application No. 2000-92272 filed on Mar. 29,2000.

FIELD OF THE INVENTION

The present invention relates to an organic waste processing method anddevice which efficiently turn organic waste such as scraps of food andraw garbage into compost in a relatively short time by fermentationdisposal.

DESCRIPTION OF PRIOR ART

For disposal of organic waste such as leftovers and raw garbage, thereare variety of methods such as method by electrically powered rawgarbage disposal device and method by directly applying underground. Asone of the methods, there is a fermentation disposing method that canturn organic waste into safe compost.

However, simply operating fermentation disposing method could bringproblems such as decay of organic waste and infestation of maggots.Especially for an operation of fermentation disposing method, it isnecessary to be knowledgeable about characteristics of aerobicmicroorganism and raw garbage compost (for example, the principle ofmicroorganism that elevates temperature by giving off fermentation heatwhen environmental status is developed; and the fact that whenfermentation disposal is operated in a tank, the fermentation disposalproceeds evenly between top part, middle part, and bottom part), andbeing skilled in the mechanical technology alone is insufficient.Therefore, for instance, ignoring the fermentation temperature ofaerobic microorganism and simply applying heat by a heating device couldcause delay in disposing time and rise in running cost, and makeindustrialization of production line difficult.

The present invention is in consideration of the above. This inventionavoids decay of organic waste and infestation of maggots, and preventsdelay in disposing time and curbs the rise of running cost, andmoreover, this invention aims to provide organic waste processing methodand device which could be easily industrialized.

The present invention also aims to provide organic waste processingmethod and device which is capable of large amount processing, 24 hourscontinuous processing, and which could significantly reduce facility andprocessing cost, by providing massive and continuous processing systemthat is not restricted to fermenter capacity.

DISCLOSURE OF THE INVENTION

To achieve the above-mentioned task, an organic waste processing methodaerobic ferments organic waste and turns into compost, by using a numberof roughly cut-end inverted cone shaped processing tanks that haveorganic waste with aerobic microorganism implanted aligned, motor to beset up on either top or bottom of each processing tank, rotating shaftsupported by either top or bottom of each processing tank at least thatrotate by motor drive, and by stirring blades that are installed to therotating shaft and mix aerobic microorganism and organic waste. Theinvention is characterized in that it puts in organic waste more thanits intake capacity into the upstream processing tank, transports a partof organic waste from the outlet at the upper part of the peripheralwall of the upstream processing tank to the downstream processing tankplaced adjacent by centrifugal force of stirring blades, and repeatsdepending on the a number of processing tanks.

The invention uses a number of processing tanks that have organic wastewith aerobic microorganism implanted and that aerobic ferment organicwaste and turn into compost, and is characterized in that a number ofprocessing tanks are aligned and the outlet at the upper part of theperipheral wall of the upstream processing tank and the inlet on the topof downstream processing tank placed adjacent are connected, eachprocessing tank is formed in the shape of roughly cut-end inverted coneand a motor is set up on either top or bottom of each processing tank,rotating shaft is supported by either top or bottom of each processingtank at least that rotate by motor drive, and stirring blades areinstalled to the rotating shaft that mix aerobic microorganism andorganic waste.

In addition, it is desirable to place a number of thermo sensors on theinner peripheral wall of each processing tank and to align these thermosensors vertically at specified intervals.

Moreover, it is desirable to install an insulating material to theperipheral wall of each processing tank and substantially seal organicwaste in these processing tanks.

Furthermore, it is possible to install cutter blades that grind and mixaerobic microorganism and organic waste to rotating shaft and/orstirring blades.

The aerobic microorganisms could be various aerobe, filamentousbacteria, or actinomycetes. Organic wastes include leftovers, fish head,pig bone, livestock dropping, sawdust, cardboard, raw garbage, and anyother organic waste. Organic waste could be persistent or not. A numberof processing tanks could be three, five, or six as long as there aremore than two. Also, stirring blades are mainly plural in number, but itdoes not especially specify the number. Also, stirring blades are mainlyplural in number, but it does not especially specify the number.

According to the invention, large amount of organic waste iscontinuously put in and expelled in a number of connected processingtanks instead of a single processing tank. Compared to the compostingdisposal using one processing tank, the fermentation efficiency could beraised. In addition, fermentation disposal could be done unlimited tothe capacity of processing tank because large amount of organic waste iscontinuously transported in a number of processing tanks from upstreamto downstream. Moreover, continuous fermentation disposing eliminatesthe need to put in and expel organic waste, speeds up the increase offermentation temperature of organic waste, and makes it possible toshorten the process when processing the same amount.

According to the invention, a number of thermo sensors are placed on theinner peripheral wall of each processing tank and are aligned verticallyat specified intervals, therefore, it is possible to grasp thetemperature distribution of top, center, and bottom, or top and bottomof organic waste and control the motor rotation.

According to the invention, a insulating material is installed to theperipheral wall of each processing tank and organic waste issubstantially sealed in these, therefore, it is possible to avoid theheat caused by organic waste decomposition from escaping outside. Hence,it can increase the fermentation temperature of organic wasteapproximate linearly under small heat loss decomposition condition.Moreover, fermentation is done under substantially sealed condition, inother words, a pressure retaining condition, therefore, it is possibleto increase fermentation temperature in a short time (under a certaincondition, increase higher than 100 degrees Celsius in less than 90minutes).

Furthermore, according to the invention, singular or plural number ofcutter blades that grind and mix aerobic microorganism and organic wasteare installed directly or indirectly to rotating shaft and/or stirringblades, therefore, it is possible to accelerate organic wastefermentation with relatively small rotational resistance.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is an explanatory diagram showing an embodiment of an organicwaste processing method and device according to the present invention.

FIG. 2 is a sectional explanatory diagram showing an embodiment of anorganic waste processing method and device according to the presentinvention.

FIG. 3 is an explanatory diagram showing stirring blades in otherembodiments of an organic waste processing method and device accordingto the present invention. FIG. 3( a) is an explanatory diagram showingslanted puddle type stirring blades; FIG. 3( b) is an explanatorydiagram showing turbine type stirring blades; and FIG. 3( c) is anexplanatory diagram showing anchor type stirring blades.

FIG. 4 is an explanatory diagram showing cutter blades in otherembodiments of an organic waste processing method and device accordingto the present invention.

FIG. 5 is a graph of an embodiment of an organic waste processing byusing single processing tank.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A detailed explanation of the best mode for carrying out the presentinvention is made referring to the drawings. An organic waste processingmethod and device in the present embodiment, as shown in FIGS. 1 and 2,processing tanks 3, 3A, and 3B that substantially seal organic waste 2with aerobic microorganism implanted beforehand are aligned fromupstream to downstream, outlet 14 on the upper part of each medium-sizedprocessing tank 3, 3A, 3B, and 3C and inlet 9 on the top part ofprocessing tanks 3A, 3B, and 3C placed downstream and adjacent areconnected by passage 4, motor 17 is installed on the bottom part of eachprocessing tank 3, 3A, 3B, and 3C, and at the same time, rotating shaft19 that rotates by motor 17 drive is set up passing through the top andbottom parts inside each processing tank 3, 3A, 3B, and 3C, a number ofstirring blades 21 that mix aerobic microorganism 1 and organic waste 2are installed on rotating shaft 19, and a large amount of organic waste2 is continuously aerobic fermented and turned into compost.

Aerobic microorganism 1 is comprised of various aerobes that requireoxygen, filamentous bacteria, and actinomycetes. This aerobicmicroorganism 1 is dominant state in nature because it is characterizedin that it has respiration that is biologically highest in energyefficiency, and it has proliferation rate that is faster compared toanaerobes.

A number of processing tanks (in the present embodiment, four) 3, 3A,3B, and 3C are, as shown in FIG. 1, set up on the stand 5 in a straightsingle horizontal row. From this setting, a number of processing tanks3, 3A, 3B, and 3C have the top processing tank 3 at the highestposition, processing tanks 3A and 3B at positions gradually lowered thanthe one before, and the lowest processing tank 3C at the lowestposition.

Each processing tank 3, 3A, 3B, and 3C is, as shown in FIG. 2, formed bysuch materials as aluminum, aluminum alloy, and steel in the shape ofhollow and roughly cut-end inverted cone with the height of 100 cm orless. Each processing tank 3, 3A, 3B, and 3C is equipped withcylindrical large diameter part 6 placed in the upper section, roughlycut-end inverted cone shaped small diameter part 7 is placed integrallyand continuously in the lower section, and is functioned so that moreorganic waste 2 can be stored at the large diameter part 6 than organicwaste 2 to be blended at the small diameter part 7. To explain thispoint, organic waste 2 such as raw garbage is characterized in that itreduces volume by grinding and mixing, and reduces more when thefermentation disposal progresses. Therefore, each processing tank 3, 3A,3B, and 3C has organic waste 2 in the small diameter part 7 and organicwaste 2 in the large diameter part 6 are mixed in a swirl when stirredand reduced in volume, and at the same time, large diameter part 6 is aspace to guarantee contact with oxygen.

Each processing tank 3, 3A, 3B, and 3C comprises axis supporting part 8for rotating shaft 19 at the flat top center part, axis supporting part8 having a bearing built in, on the flat top part from the center tooutward, an inlet 9 for organic waste 2, window 10 for observing inside,an installing nozzle 11 for the thermometers, a lighting nozzle notshown, a controlling panel 12, and an expel duct 13 to expel carbondioxide, steam and so on that are inside processing tanks 3, 3A, 3B, and3C. The controlling panel 12 controls motor 17 and so on. At the upperpart of peripheral wall, each processing tank 3, 3A, 3B, and 3C, anoutlet 14 to adjust degrees of the lid opening is set up long sideways,and the compost is expelled downstream from this outlet 14 to processingtank at the lower position. For example, when planning to put in 60 kgof organic waste 2, this outlet 14 may be formed in the range of 20 cmfrom the top part of peripheral wall on each processing tank 3, 3A, 3B,and 3C.

At the inner walls of each processing tank 3, 3A, 3B, and 3C, a numberof thermo sensors 15 such as thermistor are installed vertically atspecified intervals, and these thermo sensors 15 functions to outputdetection signals to the controlling panel 12. Moreover, at the outerwalls of each processing tank 3, 3A, 3B, and 3C, an insulating material16 made of asbestos and glass wool is integrally applied around, andthis insulating material 16 effectively avoids heat from transportingout from processing tanks 3, 3A, 3B, and 3C.

The motor 17 is made of cheap general-purpose AC motor or DC motor,loaded on the stand 5, and able to mix organic waste 2 well enough by,for example, rotating at a rate of about 110 revolutions per minute.This motor 17 is connected with decelerator 18 and an output axis ofthis decelerator 18 is placed at the bottom center of processing tanks3, 3A, 3B, and 3C. Furthermore, rotating shaft 19 has its upper partsupported by the bearing of axis supporting part 8, its lower partsupported by the bearings of processing tanks 3, 3A, 3B, and 3C, and atthe same time connected to output axis of the decelerator 18 throughjoint 20 and the sealing device. To this rotating shaft 19, a number ofstirring blades 21 pointing in the diameter direction of processingtanks 3, 3A, 3B, and 3C are set up radiately through a connector, andeach of this metal stirring blade 21 mixes aerobic microorganism 1 andorganic waste 2.

In the above-mentioned structure, to dispose organic waste 2 such asleftovers and raw garbage, first of all empty all processing tanks 3,3A, 3B, and 3C, implant aerobic microorganism 1 to the organic waste 2such as raw garbage, and put in a large amount of organic waste 2 intothe inlet 9 of the most upstream processing tank 3 continuously.Regarding the amount of organic waste 2 to put in, it is desirable toput in as much amount as possible over its capacity because largeramount accelerates fermentation disposal progress more. If fish headsand pig bones are in the organic waste 2, it is recommended to grindthem to the moderate size by a grinder (for example, jaw crusher, corncrusher, or hammer mill) beforehand.

Moreover, if the percentage of moisture content of organic waste 2 isover 66%, drain or dry to adjust the percentage of moisture content oforganic waste 2 to 45˜65% or less (moisture standard) so that aerobicmicroorganism 1 can be active and an offensive odor can be avoided.Also, implantation of aerobic microorganism 1 can be done before orafter such process. At the time of implanting aerobic microorganism 1,it is possible to ensure the balance of carbon and nitrogen by mixingcarbon source such as dead leaves and dead grasses to control dispersionof nitrogen.

After putting more than tank's capacity of organic waste 2 into the mostupstream processing tank 3 with the same pressure kept, drive the motor17 to continuously rotate the rotating shaft 19 at the rate of about 110revolutions per minute, grind and mix organic waste 2 and aerobicmicroorganism 1 well with stirring blades 21 to put properties oforganic waste 2 in order, put conditions of decomposition by aerobicmicroorganism 1 in order to make organic waste 2 more smaller, andfermentation dispose organic waste 2 at the specified temperature.Incidentally, ignoring the fermentation temperature of aerobicmicroorganism and simply applying heat by a heating device could causedelay in disposing time and rise in running cost, and makeindustrialization of production line difficult. In the presentinvention, however, organic waste 2 is self heat generated by a simplestructure and the fermentation temperature is controlled. At thisfermentation disposing, namely, because organic waste 2 is self heatgenerated by a simple structure, not heated up outside by some heatingdevice, transitions such as increase, constancy, and decrease in itsfermentation temperature are observed by a number of thermo sensors 15ceaselessly. To increasing fermentation temperature of organic waste 2,and to make the processing time short, rotational rate of the motor 17is raised up, in other words, rotational rate of rotating shaft 19 isincreased manually or by automatic control. Conversely, to decrease thefermentation temperature of organic waste 2 for the economic/costreasons, lower rotational rate of the motor 17, in other words,rotational rate of rotating shaft 19 is dropped manually or by automaticcontrol.

Furthermore, when more than tank's capacity of organic waste 2 is putinto the most upstream processing tank 3 continuously, overflowedorganic waste 2 is expelled, by potential energy and horizontalcentrifugal force of stirring blades 21, from the outlet 14 of theprocessing tank 3 to the inlet 9 of the adjacent and downstreamprocessing tank 3A. This is repeated depending on the number ofprocessing tanks 3, 3A, 3B, and 3C, and the organic waste 2 continuouslyexpelled to the most downstream processing tank 3C. As organic waste 2is transported continuously through processing tanks 3, 3A, 3B, and 3C,the amount of microorganism is increased and the fermentationtemperature rises gradually (for example, 20, 40, 65, and 90 degreesCelsius) and the first fermentation is completed.

Next, organic waste 2 is aerobic fermented and turn into compost, andwhen compost is obtained, compost shown by the arrow is expelled fromeach processing tank 3, 3A, 3B, and 3C. After that, by putting compostinto fields, fertilizer components are provided to crops andmicroorganisms in the soil are activated. Repeat the above-mentionedprocedures as much as necessary.

According to the above-mentioned structure, a large amount of organicwaste 2 can be continuously put in and continuously expelled for 24hours and on, fermentation efficiency can be largely improved comparedto each composting disposal. Also, a number of processing tanks 3, 3A,3B, and 3C continuously transport large amount of organic waste 2 fromupstream to downstream, therefore fermentation disposal can be operatedwithout a limit of capacity in processing tanks. Moreover, when one ofthe processing tanks failed, it can evade that processing tank andcontinuously transport a large amount of organic waste 2, and it canavoid stopping the system as a whole. Furthermore, since it is acontinuous fermentation disposal, putting in and expelling organic waste2 each time is not necessary, fermentation temperature of organic waste2 is faster, and can count on shortening the process. What is more, inthe second and the steps, remaining heat energy can be used andtemperature fall by putting organic waste is truly small.

Organic waste 2 is self heat generated by a simple structure, not heatedup outside by some heating device, and its fermentation temperature iscontrolled by the motor 17, therefore, it is possible to largely avoiddelay in the processing time and rise in the running cost. Also, sinceit is a simple structure, it can expect the production line to beindustrialized. Moreover, it is possible to easily obtain compost withless offensive odor density because organic waste 2 is self heatgenerated at high temperature. Therefore, under such high temperaturecondition obtained by organic waste 2 self generating heat, unlikeraising temperature by heating from outside, solid and liquid of organicwaste 2 are reduced well balanced and high temperature is reachedwithout losing decomposition conditions of microorganisms. As a result,volatile component among easily decomposed component in the organicwaste 2, and compost with low offensive odor density is easily obtainedafter the disposal. From all the above, improvement of the soil usingthe compost, therefore create productive agriculture, avoid agriculturalchemical contamination, improve agricultural self-sufficiency, andaccelerate assimilation of global warming gas from plants.

In the above-mentioned embodiment, a large amount of organic waste 2 wascontinuously put into the inlet 9 of the most upstream processing tank3, however it is not limited to that and a large amount of organic waste2 can be put into inlet 9 of each processing tank 3, 3A, 3B, and 3C.Moreover, processing tanks 3, 3A, 3B, and 3C can be set up on the stand5 in 20˜50 degrees vertical inclination to lighten the burden imposed onstirring blades 21. Motor 17 and decelerator 18 can be positioned on thetop center of disposition tanks 3, 3A, 3B, and 3C. As shown in FIGS. 3(a), (b), and (c), number and shape of stirring blades 21 can be changedsuitably. As shown in FIG. 4, one or a number of cutter blades 22 thatgrind and mix aerobic microorganism 1 and organic waste 2 can beinstalled on rotating shaft 19 and/or stirring blades 21 and cut down oromit the grinding device.

An explanation of the embodiment of organic waste processing method anddevice according to the present invention will be made in the following.

As shown in FIG. 1, four processing tanks 3, 3A, 3B, and 3C are alignedserially from upstream to downstream having outlet 14 on the upperperipheral wall of each processing tank 3, 3A, and 3B and inlet 9 on thetop part of processing tanks 3A, 3B, and 3C placed adjacently and thedownstream from the former of each tank are connected by passage 4, havemotor 17 installed on the bottom part of each processing tank 3, 3A, 3B,and 3C, and at the same time, rotating shaft 19 that rotates by motor 17drive is set up passing through the top and bottom parts inside eachprocessing tank 3, 3A, 3B, and 3C, and a number of stirring blades 21that mix aerobic microorganism 1 and organic waste 2 are attached onrotating shaft 19. By using this organic waste processing device, alarge amount of organic waste 2 is continuously aerobic fermented andturned into soil, and change of fermentation temperature of organicwaste 2 is measured.

By using single processing tank, a large amount of organic waste iscontinuously aerobic fermented and turned into soil, and change offermentation temperature of organic waste is shown in FIG. 5. In thedisposal, fermentation temperature was set at 80 degrees Celsius anddisposal completion time was set up at 5 minutes and over.

Result

Reduction of Average Processing Time

It took 4 hours and 30 minutes to process organic waste by using fourprocessing tanks to the present invention, while it took 5 hours and 30minutes by comparison with single processing tank. The average time wasabout 67 minutes.

Increase of the Lowest Temperature

In putting in organic waste 2, the fall of the disposing temperature inthe second disposal or more was less than that in the first disposal.This is because the quantity of heat in the processing device was high.

Increase of the Highest Temperature

In a generally use of the processing device, the temperature raised welland did not take too long to reach 90 degrees Celsius. Bad molds areusually sterilized by heat of 90 degrees Celsius and over.

Consideration Based on FIG. 5

In the continuous fermentation disposal, compared with singlefermentation disposal, it does not need to take out or put in outsidethe processing device. Therefore the processing time by a number ofprocessing tanks is shortened than that by single processing tank, whenprocessing the same amount the original way. Also, change offermentation temperature of organic waste by using single processingtank shown in FIG. 5 included the periods between “Take Out and Put in”.In the present invention, those processes are not necessary.Furthermore, 85 degrees Celsius and over of fermentation temperature isnot necessary to dispose organic waste. So, it was calculated60+40+50+30=180 minutes in total of four tanks from putting in organicwaste to increasing inside temperature of each processing tank up to 85degrees Celsius, therefore average time per tank was 45 minutes.

INDUSTRIAL APPLICABILITY

The present invention according to claim 1 or 2, has effects such as nodecay of organic waste and no infestation of maggots, and no delay inprocessing time and no rise in running cost. Also, since it is arelatively simple structure, it can expect the production line to beindustrialized.

Moreover, it is capable of large amount processing and 24 hourscontinuous processing, and can largely cut down facility and processingcosts.

1. An organic waste processing method for fermenting organic waste andturning it into compost, comprising the steps of: providing a pluralityof processing tanks, each processing tank being formed of a conicalvessel disposed with its narrow end as a bottom of the vessel and beingsealed at its top end with a lid that includes a material inlet, saidtank further including an outlet located on an uppermost surface of aperipheral wall of the tank, a drive motor, a rotatable shaft connectedto the motor, and stirring blades installed on the shaft, the motor,shaft, and blades being constructed extending in a diametral directionof the tank such that centrifugal force generated by the blades allows apart of the material being processed to be mixed in an upward swirl inthe tank and to be discharged out of the tank through the outlet,wherein the inlet of each tank vessel in processing succession isprovided at an elevation lower than that of the outlet of the precedingtank vessel, and processing organic waste aerobically withmicroorganisms mixed therein in processing succession through saidplurality of processing tanks.
 2. An organic waste processing devicecomprising: a plurality of processing tanks, each processing tank beingformed of a conical vessel disposed with its narrow end as a bottom ofthe vessel and being sealed at its top end with a lid that includes amaterial inlet, said tank further including an outlet located on anuppermost surface of a peripheral wall of the tank, a drive motor, arotatable shaft connected to the motor, and stirring blades installed onthe shaft, the motor, shaft, and blades being constructed extending in adiametral direction of the tank such that centrifugal force generated bythe blades allows part of the material being processed to be mixed in anupward swirl in the tank and to be discharged out of the tank throughthe outlet, wherein the inlet of each tank vessel in processingsuccession is provided at an elevation lower than that of the outlet ofthe preceding tank vessel.
 3. An organic waste processing deviceaccording to claim 2, wherein a number of thermo sensors are placed onan inner part of the peripheral wall of each processing tank alignedvertically at a specified interval.
 4. An organic waste processingdevice according to claim 2, wherein an insulating material is installedon the peripheral wall of each processing tank to substantially sealorganic waste being processed in the tank.
 5. An organic wasteprocessing device according to claim 2, wherein cutter blades areinstalled on the rotating shaft to grind and mix aerobic microorganismsand organic waste in each processing tank.